Differential Effects of TPM, A Phosphorylated Tocopherol Mixture, and Other Tocopherol Derivatives as Excipients for Enhancing the Solubilization of Co-Enzyme Q10 as a Lipophilic Drug During Digestion of Lipid- Based Formulations

Anna Pham, Paul D. Gavin, Roksan Libinaki, Gisela Ramirez, Jamal T. Khan, Ben J. Boyd

Research output: Contribution to journalArticleResearchpeer-review


BACKGROUND: The tocopherol-based excipient, TPM, when incorporated into a medium-chain triglyceride (MCT)-based lipid formulation, has been previously shown to improve the solubilization of Coenzyme Q10 (CoQ10) during in vitro digestion which is strongly correlated with enhanced exposure in vivo. METHODS: The current study aimed to gain further understanding of the MCT + TPM co-formulation, by assessing the formulation performance under fasted and fed in vitro digestion conditions, with different drug and excipient loading levels. Natural and synthetic-derived TPM were equivalent, and with d-α- tocopherol polyethylene glycol 1000 succinate (TPGS) outperformed other derivatives in enhancing the solubilisation of CoQ10 during digestion. RESULT: Fed conditions significantly improved the solubility of CoQ10 during in vitro digestion of the formulation in comparison with fasted conditions. The addition of TPM at 10% (w/w) of the total MCT + TPM provided optimal performance in terms of CoQ10 solubilization during digestion. CONCLUSION: The results further highlights the potential of TPM as an additive in lipid formulations to improve the solubilization and oral bioavailability of poorly water-soluble compounds.

Original languageEnglish
Pages (from-to)628-636
Number of pages9
JournalCurrent Drug Delivery
Issue number7
Publication statusPublished - 1 Jan 2019


  • digestion
  • formulation
  • lipids
  • phosphorylated tocopherol
  • poorly water-soluble drug.
  • TPM

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